Fluorescent lamps are removed from conventional lamp holders on fluorescent lighting fixtures by rotating the lamp such that bi-pins of the lamp become aligned with a slot in the lamp holder, thereby allowing the bi-pins to pass through the slot and freeing the lamp. While installation and removal of fluorescent lamps is therefore relatively simple, conventional fluorescent lamp holders give rise to the possibility of the lamp being inadvertently rotated and disengaged from the lamp holder, such as during shipping or during an earthquake, for example. Such inadvertent disengagement of the lamp from the lamp holder can cause injury to persons below such lamps, especially in the case where such lamp fixtures are installed on a ceiling or high upon a wall. As such, an inexpensive and simple means by which to "lock" fluorescent lamps in their lamp holders is needed.
A locking means for fluorescent lamps is disclosed in U.S. Pat. No. 3,723,945 to Detch on Mar. 27, 1973. Such a device consists of a wafer-like member that is inserted between the end of a lamp and the lamp holder. Such a device has no less than two slots for engaging the bi-pins of the lamp, as well as a lug or two guide ribs or both. In use, the slots of the device engage the bi-pins of the lamp and the lug and/or guide ribs of the device engage the lamp holder. This combination prevents the lamp from rotating with respect to the holder. However, several considerable drawbacks exist with such a device. In lamp fixture installations on a ceiling, for example, the force of gravity tends to urge such a device away from its locking position. Such a device, therefore, may become inadvertently dislodged from the lamp relatively easily. Further, as one section of such a device protrudes from the lamp holder, objects moving past a fluorescent lamp fitted with such a device might inadvertently snag the device. Such a lateral impact on a device of this type imparts a rotational force on the device and, hence, the bi-pins of the lamp. As a result, such forces actually tend to dislodge the lamp from the holder rather than preventing the lamp from rotating. Further, such a device necessarily requires two slots, one slot for each pin of the lamp and a specific configuration to match the particular lamp holder. As different sized lamps may have different spacing between pins and different lamp holder designs having different dimensions and shapes, a variety of sizes of such devices must be manufactured and correctly chosen from by the end user.
Clearly, then, there is a need for a locking device for fluorescent lamps that does not tend to become dislodged once installed. Such a needed device would not have protruding portions that could inadvertently be snagged by passers by. Further, such a needed device would fit all bi-pin type lamps, and would make suitable provision for lamp holders having different dimensions and sizes. Such a needed device would be extremely inexpensive to manufacture, and would not interfere in the normal operation of the lamp. The present invention fulfills these needs and provides further related advantages.